Automatically controlled ash removing grate



June 9, 1953 F. J. WEST ETAI.

AUTOMATICALLY coNTRoLLED Asl-x REMovING GRATE Filed Aug, v23, 1949 2Sheets-Sheet 1 n f f /l \b NN ////////////////W m f Am June 9, 1953 F.J. .wx-:sT ETAL AUTOMATICALLY CONTROLLED ASH REMOVING CRATE Filed Aug.2s, 1949 2 Sheets-Sheet 2 Patented June 9, 1953 AUTOMATICALLY CONTROLLEDASH REMOVING GRATE Frederick Joseph West and Ernest West, Manchester,England, assignors to Wests Gas Improveinent Company Limited,Manchester, England, a British company Application August 23, 1949,Serial No. 111,906 In Great Britain September 6, 1948 6 Claims.

This invention relates to gas producers of the type known as mechanicalproducers in which the grate is revolved in order to elect extraction ofash.

The object of the present invention is to provide automatic means forcontrolling the ash level in the producer within narrow limits whichincreases the efficiency of the producer and enables the dimensions ofthe latter to be reduced for a given throughput.

The invention comprises the arrangement in the water jacketed wall ofthe producer at about the desired level of the top of the ash bed, of abulb containing an expansible fluid which through suitable meanscontrols the speed of Operation of the ash extracting grate in order tomaintain the level of the top of the ash bed where desired.

The invention further comprises the provision of means for withdrawingthe bulb to a greater or less extent into the water jacket should thetemperature to which the bulb is subjected become excessive.

The invention further comprises the provision of over-riding handcontrol means which permit the grate speed to be hand adjusted asrequired.

The invention further comprises the arrangement in which the uid fromthe bulb acts upon one side of a diaphragm, the other side of whichdisplaces a fluid which acts upon a plunger controlling the rate ofoutflow of the exhaust fluid from a hydraulic motor driving the producergrate.

The invention further comprises the interconnection of the plunger by alever with a second lever which can be held in an inoperative positionby a hand operated cam or its equivalent when the lever end moves in anelongated slot in the second plunger, the latter when released balancingthe hydraulic pressure on the rst plunger and allowing the latter to bemoved by hand to control the speed of the motor driving the producergrate.

The invention further comprises the arrangement of the lever upon ashaft which turns an indicator of grate speed, with braking meanspreventing free movement of said shaft when the second plunger isreleased to allow of hand control of the speed of the grate.

The invention further comprises connecting the diaphragm casing rigidlyto a cylinder in which is a xed abutment, with a spring between thecylinder and abutment so arranged that when the pressure of fluidproduced by move- CII ment of the diaphragm is excessive, such pressureacting between the cylinder and abutment against the spring pressurewill cause the diaphragm casing to move to withdraw the bulb to agreater or less extent into the water jacket around the producer and soprevent damage to the bulb.

Referring to the accompanying explanatory drawings:

Figure 1 illustrates in sectional elevation a portion of a gas producerwith control means thereon in accordance with this invention.

Figure 2 illustrates the control means to an enlarged scale and ingreater detail.

Figure 3 is a view at right angles to Figure 2 showing a further portionof the control means.

It will be appreciated that on the drawings Figures 2 and 3 arediagrammatic only and not to scale. They serve to illustrate the generalarrangement of the grate control means in accordance with thisinvention.

VThe producer comprises a revolving grate a, a gas oi take by throughwhich the producer gas is delivered across and through one side of theproducer, a fuel feed inlet c and a water jacketed combustion zone.

We provide in the water jacketed wall d of the producer at about thedesired level oi the top of the ash bed a bulb e containing a suitableexpansible fluid and cause such fluid through suitable means to controlthe speed of operation of the ash extracting grate in order to maintainthe level of the top of the ash bed Where desired.

As shown in detail in Figure 2, the expansible fluid presses upon oneside of a diaphragm e1, the other side of which presses upon a fluid ina pipe f and casings g and h. If the pressure of the uid in the casing gis suicient to overcome the spring i which bears at one end against thehead y' of the iixed abutment lc, the casing is moved to the right inFigure 2 and by means of the rigid pipe m carries with it the casing nof the diaphragm e1 and the mercury or like bulb e, so that such bulb isdrawn back a short distance from the hot zone of the producer and istherefore subjected to a lower temperature. This arrangement preventsdamage to the bulb due to exposure to excessive temperature. The fluidpressure in the pipe f also tends to depress the plunger o in the casingh against the pressure of the spring p. The position of the plungerdetermines the speed of the motor which turns the revolving grate u, andso the rate of ash extraction from the producer. For example, the gratemay be turned by a hydraulic motor, indicated schematically at I9,Figure 1 and the rate of reciprocation of the motor as described belowmay be regulated by controlling the rate at which the hydraulic uid canpass to exhaust by pipe 20. Thus in Figure 2, the plunger o has aperipheral groove q thereon and the hydraulic iluid which is exhaustingto atmosphere has to pass from the branch r to the branch s via suchperipheral groove, If the plunger o is in a raised position, the lengthof the peripheral groove through which the fluid has to travel is shortand so very little obstruction or throttling of the exhaust occurs;therefore the hydraulic motor operates with maximum speed, whereas whenthe plunger o is in its lower position as shown, the exhausting fluidhas to pass through a considerable length of the peripheral groove whichacts to obstruct or throttle such exhaust and therefore to slow down thespeed of the hydraulic motor driving the grate a, of the producer.

The plunger o is connected by the lever t tov a second plunger u whichcan be supportedy and put out of action byv a cam v. When so supported,the end of the lever t can move freely inthe slot v1 in the plunger u`without moving the latter. The cam v is turned by a handle or hand wheelw, Figure 3 on a shaft which has a pointer y thereon to indicate theposition of thev cam.v

When the cam c is removed from the position in which it supports theplunger u, the latter is freed so that the hydraulic pressure exerts abalancing action between the plungers o and u, and then the lever t canbe operated by hand to control the speed of the motor driving the gratea.

The spring p, when the cam v is removed from beneath the plunger u, willtend to turn the lever t and the shaft a on which it is secured and sothrough the quadrant Z, pinion 3, andk shaft 4 turn the indicator 5moving over the dial 8 which gives indications of grate speed. To'-prevent the setting of the parts being altered automatically by thespring p when the cam v is released from the plunger u, we provide a camI on the. shaft 9:

which operates a lever 8 fulcrummed at 9 andy y carrying a brake pad Ii! adapted to engage a.

brake drum H on the indicator shaft 4. When the cam v holds the plungeru in its raised position, the cam 'l holds the brake pad I0 clear of thedrum l I, but when the cam c is moved clear of the plunger u, the pad I0engages the drum l I and prevents the shaft 4 turning except under the-action of the hand wheel I2 thereon which can be used to reset theplungers o and u and so vary the speed of the motor operating theproducer grate.

It will be seen, therefore that the production of a high temperature atthe bulb e causes during normal working, when the cam c is holding upthe plunger u, the plunger o to be depressed with the result that thespeed of the motor driving the producer grate is reduced as beforeexplained whilst if the temperature at the bulb e is excessive, the bulbitself is drawn back away from the furnace zone and further into thewater jacketed zone by the action of the parts g, z', k and m aspreviously explained, so that damage to the bulb is obviated. These highand excessive temperature conditions at the bulb e indicate that the ashis being extracted too rapidly from the producer furnace so that thehigh temperature zone is becoming lower and nearer to the grate a. Onthe contrary, if the temperature at the bulb e falls below apredetermined degree, it indicates that the ash is building up on thegrate a and the high temperature zone of the furnace is rising. Theaction of the duid in the bulb e together with the associated parts isto move the plunger o to decrease the length of the peripheral slot qand so, as before explained, to speed up the motor driving the grate a.The ash level then falls and with it the high temperature Zone of thefurnace.

What we claim is:

l. In a gas producer having a grate, a hydraulic motor for turning thegrate in order to effect extraction of ash from the base of theproducer, andr a water j acketed Wall, surrounding the combustion zone,the provision of a bulb containing an expansible duid, in the waterjacketed wall at about the desired level of the top of the ash bed, adiaphragm casing, a diaphragm dividing the casing into two parts, onepart being in communication with the bulb, a housing in communicationwith the other part of the casing, a plunger in the housing adapted tobe displaced by the diaphragm through the medium of a luid, the plungercontrolling the rate of outflow of the exhaust uid from the hydraulicmotor driving the producer grate.

2. In a gas producer as claimed in claim l, the interconnection of theplunger by a lever with a second plunger, having an elongated slot andwhich can be held in an inoperative position by a hand operated cam,when the lever end moves in the elongated slot in the second plunger,the latter when released balancing the hydraulic pressure on the firstplunger and allowing the latter to be moved by hand to control the speedof the motor driving the producer grate.

3. In a gas producer as claimed in claim l, the arrangement of the leverupon a shaft which turns an indicator of grate speed, with braking meanspreventing free movement of said shaft when the second plunger isreleased to allow of hand control of the speed of the grate.

4. In a gas producer as claimed in claim 1, a cylinder to which thediaphragm casing is rigidly connected, a xed abutment in the cylinder,and a spring between the cylinder and abutment so arranged that when thepressure of duid produced by movement of the diaphragm is excessive,

such pressure acting between the cylinder and abutment against thespring pressure will cause the diaphragm casing to move to withdraw thebulb to a greater or less extent into the water jacket around theproducer and so prevent damage to the bulb.

5. In a gas producer having a grate which is turned by power in order toelect extraction of ash from the base of the producer, and a waterjacketed wall surrounding the combustion zone, the provision of a bulbcontaining an expansible fluid, in the water jacketed wall at about thedesired level of the top of the ash bed, a pressure responsive device ina casing connected with said bulb, and means actuated by said device forcontrolling the speed of operation of the ash extracting grate in orderto maintain the level of the top of the ash bed where desired, and meansfor withdrawing the bulb to a greater or less extent into the waterjacket should the temperature to which the bulb is subjected becomeexcessive.

6. In a gas producer having a grate which is turned by power in order toeffect extraction of ash from the base of the producer, and a waterjacketed wall surrounding the combustion zone, the provision of a bulbcontaining an expansible fluid, in the water jacketed Wall at about thedesired level of the top of the ash bed, a pressure responsive device ina casing connected with said n) bulb, and means actuated by said devicefor controlling the speed of operation of the ash extracting grate inorder to maintain the level of the top of the ash bed where desired, andhand control means which over-ride the automatic `control means andpermit the grate speed to be hand adjusted.

FREDERICK JOSEPH WEST. ERNEST WEST.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date Wallis Jan. 11, 1910 Daae July 14, 1931 Van Ackeren Sept. 13,1932 Corbett Sept. 18, 1934 Wolfe Dec. 11, 1934 Grine et al Dec. 3, 1935Reid, Jr Mar. 23, 1937

